/*  
 * Copyright 2008 CoreMedia AG, Hamburg
 *
 * Licensed under the Apache License, Version 2.0 (the License); 
 * you may not use this file except in compliance with the License. 
 * You may obtain a copy of the License at 
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0 
 * 
 * Unless required by applicable law or agreed to in writing, software 
 * distributed under the License is distributed on an AS IS BASIS, 
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
 * See the License for the specific language governing permissions and 
 * limitations under the License. 
 */

package com.coremedia.iso.boxes;

import com.coremedia.iso.IsoTypeWriter;
import com.coremedia.iso.boxes.sampleentry.SampleEntry;
import com.googlecode.mp4parser.FullContainerBox;

import java.nio.ByteBuffer;

/**
 * The sample description table gives detailed information about the coding type used, and any
 * initialization information needed for that coding. <br> The information stored in the sample
 * description box after the entry-count is both track-type specific as documented here, and can
 * also have variants within a track type (e.g. different codings may use different specific
 * information after some common fields, even within a video track).<br> For video tracks, a
 * VisualSampleEntry is used; for audio tracks, an AudioSampleEntry. Hint tracks use an entry format
 * specific to their protocol, with an appropriate name. Timed Text tracks use a TextSampleEntry For
 * hint tracks, the sample description contains appropriate declarative data for the streaming
 * protocol being used, and the format of the hint track. The definition of the sample description
 * is specific to the protocol. Multiple descriptions may be used within a track.<br> The 'protocol'
 * and 'codingname' fields are registered identifiers that uniquely identify the streaming protocol
 * or compression format decoder to be used. A given protocol or codingname may have optional or
 * required extensions to the sample description (e.g. codec initialization parameters). All such
 * extensions shall be within boxes; these boxes occur after the required fields. Unrecognized boxes
 * shall be ignored. <br> Defined in ISO/IEC 14496-12
 *
 * @see com.coremedia.iso.boxes.sampleentry.VisualSampleEntry
 * @see com.coremedia.iso.boxes.sampleentry.TextSampleEntry
 * @see com.coremedia.iso.boxes.sampleentry.AudioSampleEntry
 */
public class SampleDescriptionBox extends FullContainerBox {
  public static final String TYPE = "stsd";

  public SampleDescriptionBox() {
    super(TYPE);
  }

  @Override
  protected long getContentSize() {
    return super.getContentSize() + 4;
  }

  @Override
  public void _parseDetails(ByteBuffer content) {
    parseVersionAndFlags(content);
    content.get(new byte[4]);
    parseChildBoxes(content);
  }

  @Override
  protected void getContent(ByteBuffer byteBuffer) {
    writeVersionAndFlags(byteBuffer);
    IsoTypeWriter.writeUInt32(byteBuffer, boxes.size());
    writeChildBoxes(byteBuffer);
  }

  public SampleEntry getSampleEntry() {
    for (Box box : boxes) {
      if (box instanceof SampleEntry) {
        return (SampleEntry) box;
      }
    }
    return null;
  }
}
